Under the direction of Dr. Antoni Ribas, UCLA scientists are using the body’s natural defenses to stop cancer.

Ribas co-developed the breakthrough immunotherapy drug pembrolizumab, which essentially puts the “brakes” on the body’s immune system and harnesses its power to attack the disease.
Less toxic than conventional cancer therapies and with fewer side effects, the medication has already helped thousands of people with advanced melanoma enjoy longer lives.

The success of the drug, which is marketed under the brand name Keytruda, has also ushered in a new era of research into “combination therapies” — treatments that use two
immunotherapy medications together or use them with conventional treatments such as chemotherapy and radiation. Keytruda is being evaluated for possible use in combination therapy in more than
260 studies around the world, and it has already been approved for the treatment of non–small-cell lung cancer and other types of cancer.

“We have a mode of therapy that didn’t exist before, and now has become mainstream,” Ribas explains. He believes that immunotherapy could supplant chemotherapy and radiation as
a primary treatment for cancer within the next decade.

But now that Ribas and his team have learned so much about what pembrolizumab can do, they’ve turned their attention to better understanding what it can’t.

We have a mode of therapy that didn’t exist before, and now has become mainstream.

Their thinking: If they can figure out different ways to turn on the immune system to empower the human body to overcome resistance to the drug, treatments for several other types of cancer could
be on the horizon. The approach could lead to advances in combating breast, colon and prostate cancer, which have thus far shown resistance to immunotherapy.

Ribas, a professor of medicine and director of the cancer immunology program at UCLA’s Jonsson Comprehensive Cancer Center and of the
Parker Institute for Cancer Immunotherapy Center at UCLA, says UCLA is particularly conducive to his team’s cutting-edge research.

Antoni Ribas (right) in the lab with Assistant Professor Daniel Shin

“Here, we don’t simply go from the lab to the patient but also from the patient back to the lab,” he says. “It sounds so logical, but it’s just not happening in many
other places. We’re not just giving the drug — we have greater access to the patients, we’re getting samples that provide information about the human genome before even starting
the study, and we’re developing a much broader view of what is happening.”